Disadvantages of Wireless

One of the most obvious problems with wireless is the fact that you cannot easily control where the waves carrying your data will stop. The waves do not simply stop when they reach a wall or the boundary of a business; rather, they keep traveling into parking lots and other businesses in an expanding circle from the broadcast point. It's impossible to limit the wireless network to specific rooms in a building. With this type of network, you gain the ability to have connectivity in more places, but you lose the ability to tightly control where those waves can go.

This introduces the risk of unintended parties eavesdropping on network traffic from parking areas, streets, alleys, or any other place where a laptop can be set up to intercept the signals. Although 802.11b standards specify that the range of a broadcast is only 150–300 feet, in reality, the signal travels much farther. Beyond these distances, signals are weakened to the point that normal wireless cards cannot detect them with their small antennas. However, high-gain antennas can be used to amplify, detect, and analyze these weak signals far beyond the 300-foot range (vertically as well as horizontally). This is a serious consideration in multistory apartment buildings and offices. Even though your access point is set up in your 3rd floor apartment, its waves can potentially reach an apartment that is much higher.

Gaining access to a wireless network can be as simple as sitting in the parking lot of the intended target and monitoring the person's wireless communications. It is easy to sit in a parked car or van outside a company's main entrance and simply sniff for wireless traffic. In another frightening scenario, the person standing in your lobby might be checking his PDA for his next appointment, or he could be accessing your most sensitive data with his wireless connectivity network card. As mentioned, the normal range limit of 802.11b is approximately 300 feet, but signals can be both transmitted and intercepted from several miles away by using directional antennas. Although interception from several miles away takes much more sophisticated equipment, it is not out of the realm of possibility.

At this point, encryption is the easy fix. Who cares if someone is able to sniff your encrypted data? After all, it is all encrypted. However, serious concerns over security have been expressed about 802.11b and WEP. Vulnerabilities have been discovered that have cast doubt on the security of WLANS, even with using WEP. However, these concerns don't seem to be stopping the sales or popularity of 802.11b; the number of wireless devices is expected to grow at a high rate.

In the corporate realm, even if proper precautions are taken to ensure a secure wireless network environment, the risk of a user purchasing his own wireless AP or base station and installing it on the network without the IT staff knowing of its existence is still a concern. These are commonly referred to as rogue APs. Rogue APs lend themselves nicely to being installed by the individual user. Wireless devices are small and simple to install. A user can easily plug an AP into a network hub and set it beside his desk.